Fresh Start Accounting - Changes In Balance Sheet (Details) - USD ($) $ in Millions	Aug. 11, 2023	Sep. 30, 2023	Aug. 12, 2023	Dec. 31, 2022
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit		$ (26.5)	$ 0.0	$ (1,406.7)
Reorganization Adjustments
Reorganization, Chapter 11 [Line Items]
Gain on Settlement of Liabilities Subject to Compromise	$ 1,570.5
Net Change in Accumulated Deficit	1,659.4
Net deferred tax impacts on the effectiveness of the Plans
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	96.7
Elimination of unvested Predecessor stock compensation awards (liability classified)
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	0.8
Accrual of professional fees
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	(6.3)
Elimination of prepaid directors and officers insurance policies related to the Predecessor
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	(3.5)
Acceleration of the vesting of Predecessor equity awards upon the Effective Date
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	(2.6)
Elimination of accumulated other comprehensive income related to interest rate swaps
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	8.8
Accrual of German transfer tax
Reorganization, Chapter 11 [Line Items]
Net Change in Accumulated Deficit	$ (5.0)